Chimeric Collar

As a bonus action, the creature grows in size to
become Large, gains 2d10 + 4 temporary hit
points, can understand Draconic (but can't
speak it), and magically grows a second,
identical head next to its own that lasts for the
duration of the effect. Whenever the enlarged
creature takes the Attack action, it can make
two attacks, or it can take the Multiattack
action instead.